Wasn't it Nelson who wrote:
Something wrong with the ice cores?

The question arises after studying this site – CO2 has only risen by
5.2% in the last 200 years.:-

http://www.biokurs.de/treibhaus/180C...bayreuth1e.htm

Ice core samples show a nice steady line like they have been smoothed.
Here is a paper dealing with the subject:-

http://cdiac.ornl.gov/trends/co2/lawdome.html

The problem I have with this, is that Antarctica is a desert. It has
an average annual precipitation (snowfall is recalculated at its
“water equivalent”) is only about 2 inches per year. Snow gets blown
around in high winds giving the impression of snow fall. Cold air
cannot hold much water. If you wanted a device to rid the ice of CO2
Antarctica could be a good place to start a study.

The fact that the top layers of snow get blown about isn't a problem,
because the CO2 doesn't come from the snow itself, but from the air as
it gets captured deep in the snow layer. As mentioned in the paper, it
takes several years for a particular piece of snow to reach a depth
where it becomes sufficiently compressed that the air can no longer
diffuse in and out. At one of the sites studied in the paper, the
sealing depth is 72 metres and the age of the cores at that depth is 40
years, so the ice must be accumulating at 1.8 metres per year, rather
than 2 inches per year.

The smoothing comes about because it takes years for air to diffuse down
through 72 metres of compacted snow, and, I guess that not all nearby
air pockets get sealed at exactly the same time. So the trapped air is a
mixture of air from several years.

--
Mike Williams
Gentleman of Leisure